This invention relates to a novel can lid lifter for a hand operated can opener. More particularly, the invention is directed to a novel can lid lifter for a hand operated can opener that cuts the outer seam wall of a can, rather than the top interior lid of the can, in order to remove the lid.
Can openers are well known. In general, they comprise a traction wheel and a cutting wheel. The traction wheel when rotated acts as a reaction surface against the can and drives the can opener around the lip of the can while the sharpened cutting wheel simultaneously cuts through the can. The most common commercially available type of can opener is one that cuts the top interior lid of the can to gain access to the can contents. A main problem with this type of can opening is that the cutting blade cuts down through the lid from the top circumference thereof and tends to come into contact with the contents of the can. This is a problem if the cutting blade is dirty from previous use or has harmful bacteria on the cutting blades. A further problem is that if the cutting blade is not particularly sharp, it will not cut the lid edge cleanly and will tend to form small metal shavings that fall into and contaminate the contents of the can. The metal shavings can be harmful if ingested. Yet a further problem is that if the entire circumference of the can lid is cut, the top lid is no larger and often falls into the can contents and can be difficult and messy to remove from the interior of the can. The exterior of the can which can be dirty is exposed to the can contents, which are ultimately consumed.
To overcome these problems, can openers have been developed that cut the outside seam of the can so that the lid and part of the circumferential seam are cut and removed from the can. In this way, the cutting blade does not contact the contents of the can, there are no metal shavings that fall into the interior of the can, and the can lid does not drop into the interior of the can. Examples of this design of can opener include U.S. Pat. No. 3,719,991 to French; U.S. Reissued Pat. No. 27,504 to Smith; U.S. Pat. No. 1,935,680 to Von Wolforsdorf; U.S. Pat. No. 4,782,594 to Porucznik et al. and U.S. Pat. No. 3,510,941 to Fyfe. All of these patents disclose a can including a pin sliding in an arcuate slot for engaging and locking the can opener on the can to be opened. While these arrangements work adequately, over time and use there is a tendency for the moving parts to wear with the result that the engaging and locking function of the opener is impaired thereby leading to difficulty in cutting the can and keeping the opener in position on the can.
My U.S. Pat. No. 5,121,546, granted Jun. 16, 1992, discloses an effective solution of the above problem. In the can opener design disclosed in that patent, there are thrust surfaces and a separating means that can be introduced between the thrust surfaces. The separating means, typically a ball bearing, is introduced between the thrust surfaces and moves a movable thrust surface away from a fixed thrust surface to separate a movable wheel, usually the traction wheel, and a cutting wheel. By this method, the can opener is brought to the cutting position. The wheel can then be rotated to cut the can. While the can opener disclosed in my U.S. Pat. No. 5,121,546 has proved to be extremely effective, experiments with groups of people have shown that a certain amount of manual dexterity is required in order to effectively operate the can opener. This can be a disadvantage because many persons endeavouring to open cans, such as the elderly or handicapped, do not have a great deal of manual dexterity.
My subsequent U.S. Pat. No. 5,367,776, granted Nov. 29, 1994, discloses a can opener which requires less manual dexterity in order to be operated. The can opener comprises a housing having a handle. The cutting wheel has a cutting edge for severing a can wall, the cutting wheel defining a cutting wheel axis. The opener also has a traction wheel with a gripping surface which engages the can, the traction wheel defining a traction wheel axis. The opener includes a hand crank for rotatably mounting the traction wheel and the cutting wheel in the housing such that their axes are substantially perpendicular and the wheels are positioned adjacent and spaced apart from each other to define a gap to accept the seam of the can to be opened. One of the wheels is movable towards the other in order to engage and lock the can between the cutting wheel and the traction wheel so that the cutting wheel acts to sever the can wall. The traction wheel acts to move the can past the cutting wheel. The first thrust surface is associated with the housing and the spaced, adjacent, second thrust surface is associated with the moveable wheel. The first and second thrust surfaces comprise cooperable cam surfaces which are rotatable relative to each other to reciprocate the first and the second thrust surfaces relative to each other between a first position, where the gap is relatively wide, and a second position where the gap is narrow and the can is engaged and locked between the cutting wheel and the traction wheel. A hand crank is associated with one of the wheels to permit rotation thereof.
My third U.S. Pat. No. 6,101,727, granted Aug. 15, 2000, protects a dual-handle pump-action type can opener that can be operated by either hand and which cuts the exterior wall of the seam of a can, rather than the top lip of the can. The dual-handle pump-action can opener includes: (a) a housing having a first handle; (b) a cutting wheel associated with the housing and the first handle and having a cutting edge for severing the exterior wall of the can seam; (c) a traction wheel associated with the housing and the first handle and having a gripping surface for engaging the interior wall of the can seam; and (d) a second handle which is movable towards and away from the first handle. When the second handle is initially moved towards the first handle after the can opener is installed on the seam of the can, it causes the traction wheel to contact the interior wall of the can seam and the cutting wheel to contact the exterior wall of the can seam. On subsequent reciprocal movement of the second handle towards and away from the first handle through a series of levers and gears, the traction wheel is caused to rotate in incremental steps to advance the traction wheel along the interior wall of the can seam, thereby causing the cutting wheel also to rotate and cut the exterior wall of the can seam.
A problem with these can openers is that although they are very efficient in cutting the seam of the can lid, it is nonetheless often difficult to remove the cut can lid from the can. This is because the can has food grade sealing compound between the intersections of the lid and can body which together form the seam. This sealing compound is sticky and deters removal of the lid and part of the seam after it is cut from the can.
The invention is directed to a can opener comprising: (a) a handle; (b) a clamping lever associated with the handle; (c) a hand crank associated with the clamping lever and handle; (d) a wheel cutting blade mounted on the can opener; (e) a traction wheel which rotates when the hand crank is rotated; (f) a can lid top contact member mounted on an exterior of the can opener for contacting the cut lid of a can; and (g) a can lid lifting pin associated with the can lid top contact member for releasably catching the edge of a cut can lid.
The can lid lifting pin can have a ridge thereon which can assist in catching the edge of the can lid. The lid lifting pin can be cylindrical and can have a protrusion at the distal end thereof of a diameter greater than the diameter of the cylinder. The protrusion can be in the shape of a hemisphere.
The can opener can include a xe2x80x9cJ-shapedxe2x80x9d can abutment member associated with the wheel cutting blade and the traction wheel for assisting an operator in contacting the can opener with a can at an optimum can lid seam cutting angle. The xe2x80x9cJ-shapedxe2x80x9d can abutment member when mounted on a can, can contact the seam of the can at an end proximate to the can opener, and at a distal end, can contact the top interior of the can lid.
The can opener can include a contact face on the wheel cutting blade which rotatably bears on the exterior underside of a seam of a can. The can wall contact face can cooperate with the xe2x80x9cJxe2x80x9d shaped can abutment to movably secure the can opener to the can during the can seam shearing operation.
The invention is also directed to a can opener comprising: (a) a handle; (b) a clamping lever associated with the handle; (c) a hand crank associated with the clamping lever and handle; (d) a wheel cutting blade mounted on the can opener; (e) a traction wheel which rotates when the hand crank is rotated; and (f) a xe2x80x9cJ-shapedxe2x80x9d can abutment member associated with the wheel cutting blade and the traction wheel for assisting an operator in contacting the can opener with a can at an optimum can lid seam cutting angle.
The invention also pertains to a can lifter for use in association with a can seam cutting can opener which comprises: (a) a can lid top contact member; and (b) a can lid lifting pin associated with the can lid top contact member, the can lid lifting pin cooperating with the can lid top contact member to grip a can lid and can seam of a cut can lid.